Two of the major concerns in the packaging of potentially harmful medication or chemicals is the provision of container closures which provide acceptable seals and are both childproof and tamperproof. Childproof closures are those which cannot be opened by young children and cannot be easily opened by older children. Tamperproof closures are those which cannot be opened without destroying a telltale indicating that the closure has been previously opened.
A number of bottle closure structures have been introduced in recent years which employ various means of preventing a young child from easily opening the cap but all of these childproof closures are subject to some criticism or fault. Furthermore, none of these childproof closures are to our knowledge tamperproof.
One approach to a childproof closure is found in U.S. Pat. No. 4,106,651 to Lemons. This patent discloses a safety closure assembly in which a cap, threaded onto the neck of a container, is provided with a hinged flap having locking means which engage corresponding locking means formed on the container neck. The hinged flap is pivoted in a plane parallel to the plane of the container mouth such that engagement of the locking means prevents rotation of the cap thereby locking it in position on the container. Although childproof, this design is relatively expensive to manufacture and assemble since accurately aligned screw threads are required both on the container and cap to assure that the locking means on the cap aligns with the corresponding locking means on the container neck when the cap is fully tightened.
A second approach to a childproof closure is disclosed in U.S. Pat. No. Re. 29,793 to Pehr in which a hinged cap is adapted to close an opening in the top of a closure. The cap is hinged to the closure and includes a locking flap engageable with an outwardly extending projection formed on a sidewall of the closure neck. The locking flap of the Pehr patent is pivoted in a plane perpendicular to the plane of the container mouth so as to prohibit upward motion and opening of the cap without first disengaging the locking flap from the projection. Such disengagement is accomplished by depressing the resilient cap against a center pivot, and, owing to the resiliency of the cap, thereby separating the flap from the locking projection on the container.
The closure of this Pehr patent is a less than optimal solution to the problem of a childproof closure because it is not as safe and childproof as is desirable. One way in which a child attacks a childproof container is by using his teeth to pry the lid open. The closure of this Pehr patent may be easily attacked and readily opened by inserting the teeth beneath the edge of the locking flap and prying the flap open relative to the locking projection.
Still another problem encountered with the childproof closure of the Pehr patent is that it is not amenable to top loading. Many containers are packaged in multiple layers in a carton and the cartons are stacked one atop the other. If multiple containers having the closure of the Pehr patent are so loaded and stacked, the locking flaps may inadvertently open as a consequence of vertical compression of the cap relative to the neck of the closure, thereby disengaging the female part of the locking flap from the male projection on the neck of the closure.
It has therefore been one objective of this invention to provide a childproof closure having an improved locking mechanism which is safer and less subject to attack by small children than prior art closures.
Still another objective of this invention has been to provide an improved childproof closure which may be vertically or top loaded without causing inadvertent or accidental opening of the locking mechanism of the closure.
The bottle closure configurations of both of the above-identified patents are both relatively expensive to manufacture and while each provides a locking assembly which is childproof, neither patent includes a tamperproof indicia in combination with the childproof locking structure to indicate or act as a telltale indication of the closure having been previously opened. A bottle closure assembly having combined childproof and tamperproof structure is often desirable in packaging perishable medication or chemicals or specified quantities of material where it is necessary to prevent children from getting at the contents and also to at the time of purchase, know whether or not the contents have been tampered with in any way.
It has therefore been another objective of this invention to provide an improved childproof container closure which is readily adaptable to the addition of a telltale operative to indicate whether the contents of a container to which the closure is applied has ever been tampered with or opened after filling of the container.
Still another objective of this invention has been to provide a bottle closure assembly which is both tamperproof and childproof.
It has been another objective of this invention to provide an improved childproof closure which may be sealingly press fit into a container without any need to orient the closure onto the container.
Still another objective of this invention has been to provide a childproof closure adapted to be press fit onto the neck of a bottle or container and so configured as to provide an improved two-point seal between the closure and container to assure that the contents of the bottle do not leak.
It has been a still further objective of this invention to provide an improved snap-fit lock for securing a cap of a closure so configured that the lock cannot be snap-fit into a locked condition unless the cap is seated in a fully closed and sealed condition relative to the closure.